The present invention relates to a driving gear with two pedals fixed to pedal levers, rotating around a common axis and with a driving shaft, for bicycles or generally for vehicles driven by pedals.
There are many inventions aiming to improve conventional bicycle driving gear (two rotating pedals in opposite position). Most of these inventions try to eliminate or diminish the basic disadvantage of this gear, namely that there is a relatively short stage during the periodic motion when the depressed pedal moves in a favourable direction for the muscles of the leg. On conventional bicycles this direction is the downward pushing of the pedal, thus the effective stage is near to the horizontal position of the pedal. As this effective stage is relatively short (about 1/3 of the circle), the drive is pulsating, what is more, there are positions--so called dead points--when the depressing of neither of the pedals will result in forward drive.
Most of the improvements attempt to diminish the ineffective movements of the pedals (and of the legs), either by moving the pedals linearly up and down or by changing the length of the pedal levers. Another possibility is to alter the angular speed of the pedals according to their positions around the circle.
Because of their various disadvantages, these mechanisms could not gain ground, anyway, none of them could eliminate the dead points and the pulsating character of the drive.